1. Field of the Invention
The present invention relates to a method of preparing porous silica particles. More particularly, the present invention relates to a method of preparing mesoporous silica particles using a spray pyrolysis scheme.
2. Description of the Related Art
Pores are classified into micropores having the particle size of 2 nm or less, mesopores having the particle size of 2 nm to 50 nm, and macropores having the particle size of 50 nm or more according to the particle sizes thereof.
Meanwhile, the mesoporous silica has been applied to various fields such as a catalyst, absorption, a molecular sieve, a gas sensor, ion exchange, and the delivery of chemicals.
Various schemes have been generally known in order to prepare a mesoporous silica material in a film type, or a spherical type, as well as the bulk type. Among them, a liquid-phase synthesis scheme generally includes a scheme of simply employing a surfactant and a synthetic scheme of employing amphiphilic block copolymers. A gas-phase synthesis scheme mainly includes a synthesis scheme of employing organic particles for a template. According to the gas-phase synthesis scheme, consecutive processes are possible, and the preparation process can be easily expanded for the purpose of mass production when comparing with the liquid-phase synthesis scheme.
Meanwhile, in order to variously apply mesoporous silica particles, the porous characteristics such as the size of particles, a pore size, a pore volume, and the specific surface area must be essentially controlled. In general, to control the above porous characteristics, the size of the polystyrene organic particles used for a template has been adjusted, and the content of polymer such as styrene or polyethylene glycol (PEG) has been adjusted.
Although tetrachloride silicon (SiCl4) and alkoxysilane such as and tetraethyl orthosilicate (TEOS) have been used as the source material of silica, they represent disadvantages of strong corrosivity, high harmfulness to an environment, and a high price.
As the related art of the present invention, a manufacturing method of silica powders using an ultrasonic spray pyrolysis method has been disclosed in Korean Unexamined Patent Publication No. 10-2010-0128628 (published on Dec. 8, 2010).